The present invention relates to a method of determining the rate of rotation of vehicles. More particularly the present invention relates to a method of determining the actual rotation rates of a vehicle wherein a path sensor generates signals corresponding to the movement of the vehicle and a gyro arrangement continuously detects the orientation of the vehicle, and with the signals generated by the path sensor and by the gyro arrangement being processed in an evaluation circuit. The invention also relates to vehicle arrangements for implementing the method.
Federal Republic of Germany published patent application DE 3,111,130.A1 discloses the derivation of a vehicle rate of rotation from a gyro navigation system. The drawback in this prior art gyro system is its inherent characteristic of a time-dependent drift because of which a time dependent deviation from the desired course, particularly in driverless vehicles, cannot be avoided.
Federal Republic of Germany published patent application No. DE 3,003,287.A1, corresponding to U.S. Pat. No. 4,816,998, discloses a self-propelled vehicle in which freely running rear wheels provided with angle sensors are provided for the purpose of obtaining information about the length of the path and a circle radius for guiding the vehicle. Wheel sensors are here employed as the angle sensors. However, these wheel (angle) sensors are subject to interference if, for example, the vehicle wheel runs through a pothole. Such interference causes the wheel sensor to loose the direction information of the vehicle because, during passage through this pothole, the rate of rotation of at least one wheel is statistically changed and thus, accordingly, a high vehicle rate of rotation is reported for a short time which leads to faulty reactions on the part of the vehicle.